Process and apparatus for acid regeneration
A process and apparatus for regenerating a spent acid stream or other stream, such as a spent acid stream or other stream containing sulfur, by decomposing the spent sulfuric acid stream and/or other sulfur-containing streams to recover sulfur dioxide from the stream. Also provided is a process for preparing sulfuric acid from the sulfur dioxide recovered by the apparatus and process.
1. A process for decomposing at least one of a spent sulfuric acid stream or other sulfur-containing stream, comprising:
supplying at least one of the spent sulfuric acid stream or the other sulfur-containing stream into a furnace;
supplying oxygen-enriched combustion air into the furnace;
separately supplying pure oxygen into the furnace;
supplying a combustion fuel to the furnace;
decomposing the at least one spent sulfuric acid stream or other sulfur-containing stream in the furnace;
sensing an amount of oxygen both in the oxygen-enriched combustion air supplied to the furnace and at an outlet stream from the furnace; and
adjusting the amount of oxygen supplied to the oxygen-enriched combustion air as necessary for decomposing the at least one spent sulfuric acid stream or other sulfur-containing stream in the furnace.
2. The process of claim 1 , comprising decomposing the spent sulfuric acid stream.
3. The process of claim 1 , comprising decomposing the at least one other sulfur-containing stream.
4. The process of claim 1 , comprising decomposing both the spent sulfuric acid stream and the other sulfur-containing stream.
5. The process of claim 2 , wherein the separately supplying pure oxygen into the furnace comprises injecting the pure oxygen at or near a periphery of a primary flame of one or more burners of the furnace.
6. The process of claim 5 , wherein the oxygen-enriched combustion air is heated prior to the supplying the oxygen-enriched combustion air into the furnace.
7. The process of claim 6 , wherein prior to the supplying oxygen-enriched combustion air into the furnace, oxygen is injected into combustion air for preparing the oxygen-enriched combustion air.
8. The process of claim 5 , wherein the pure oxygen is heated prior to the supplying the pure oxygen into the furnace.
9. The process of claim 1 , wherein the oxygen-enriched combustion air and the pure oxygen are supplied to the furnace through separate piping.
10. The process of claim 1 , wherein the supplying pure oxygen is to the furnace through one or a plurality of injectors.
11. The process of claim 10 , wherein a proportion of oxygen delivered to the enriched air stream and to the one or plurality of injectors is determined based on either a measured temperature proximate a flame, or a theoretical adiabatic temperature of a fuel/air/oxygen mixture delivered through burners.
12. The process of claim 1 , wherein the supplying the oxygen-enriched combustion air and the combustion fuel are to the furnace through separate piping.